Nikon's tiny 6.1MP DSLR that proved simplicity and large photosites could produce genuinely satisfying images.
The Nikon D40 (2006) was Nikon's smallest DSLR, designed to compete with Canon's entry Rebels. Despite 6.1MP and a 3-point AF system, it earned a devoted following for excellent base-ISO quality and clean high-ISO from its large photosites.
Excellent image quality at base ISO — rich colour and pleasing tonality from the CCD sensor. No in-body AF motor means only AF-S and AF-I lenses autofocus. 2.5fps burst. No live view or video. Fixed 2.5-inch LCD.
Nikon F mount with no built-in AF motor — the critical limitation. Only AF-S, AF-I, and AF-P lenses autofocus. Manual focus required with older screw-drive lenses. 475g body. SD card. ~470 shots per charge.
Very common and extremely cheap used. Check shutter — rated ~50,000 actuations. Budget lens purchases around AF-S glass. Paired with the AF-S 35mm f/1.8G DX it produces remarkably satisfying images for learning and casual use.